The Periodic Table

Question 1

What were the two ways to categorise elements until recently?

Answer 1

1. Physical and chemical properties

2. Relative Atomic Mass

Question 2

How did Newlands arrange the elements?

Answer 2

In rows of seven.

Question 3

Why did Newlands arrange the elements in octaves?

Answer 3

He noticed that every eighth element had similar properties.

Question 4

Why did Newlands table not work?

Answer 4

The transition metals messed up the pattern.

Question 5

Why was Newlands’ work criticised?

Answer 5

1. Elements that didn’t have similar properties were grouped together
2. Non-metals and metals were mixed
3. No gaps left for undiscovered elements

Question 6

How many known elements were there in Mendeleev’s time?

Answer 6

Around 50.

Question 7

How did Mendeleev arrange the elements?

Answer 7

In order of atomic mass.

Question 8

Why was Mendeleev’s table successful?

Answer 8

Newly discovered elements fitted into gaps that he left.

Question 9

Why were the gaps clever?

Answer 9

They predicted the properties of undiscovered elements.

Question 10

Why was the periodic table largely seen as unimportant when it was first released?

Answer 10

There wasn’t much evidence to suggest that the elements really did fit together like that.

Question 11

Why is there less attraction for electrons in higher energy levels?

Answer 11

1. Increased distance

2. Increased shielding (other inner electrons)

Question 12

Why does increased distance and shielding mean in terms of reactivity?

Answer 12

Outer shell electrons are more easily lost, but it’s harder for high energy levels to gain electrons.

Question 13

What are the group one elements also known as?

Answer 13

Alkali metals.

Question 14

How do the elements change as you go down group 1?

Answer 14

1. More reactive

2. Lower melting and boiling points

Question 15

What properties do alkali metals share?

Answer 15

1. Low density
2. One outer electron
3. React with water to produce hydrogen gas
4. Form ionic compounds with non-metals

Question 16

What kind of ion do alkali metals form?

Answer 16

1+ ions.

Question 17

What colour compounds do alkali metals form with non-metals, and what colour solutions?

Answer 17

White compounds that dissolve in water to form colourless solutions.

Question 18

What is produced in the reaction between water and alkali metals?

Answer 18

1. Hydrogen gas

2. Hydroxides - alkaline solutions

Question 19

What happens when alkali metals are put in water?

Answer 19

1. Float
2. Move around surface
3. Fizzing

Question 20

What are the group seven elements also known as?

Answer 20

Halogens.

Question 21

How do the elements change as you go down group 7?

Answer 21

1. Less reactive
2. Higher melting point
3. Higher boiling point

Question 22

What kind of elements are the halogens?

Answer 22

Non-metal coloured vapours.

Question 23

What kind of bonds do the halogens form with metals?

Answer 23

Ionic bonds.

Question 24

What kind of ions do the halogens form?

Answer 24

Halide ions (1-)

Question 25

How do halogens react with other halogens in an aqueous solution of its salt?

Answer 25

More reactive halogens displace less reactive halogens.

Question 26

What properties do transition metals share?

Answer 26

1. Good conductors of heat and electricity 2. Dense, strong, shiny (more than alkali metals) 3. Less reactive (than alkali metals) 4. Higher melting points (than alkali metals)

Question 27

What is special about the ions that transition metals form?

Answer 27

They often have more than one ion.

Question 28

Why are compounds colourful?

Answer 28

Due to the transition metal ion they contain.

Question 29

What colours do transition metal ions give?

Answer 29

1. Gemstones | 2. Pottery glazes

Question 30

What other use do transition metals have?

Answer 30

Good catalysts (e.g iron, Haber process)